A method for voltage and current control in the formation process of tantalum capacitors

Abstract

This invention relates to the field of tantalum capacitor formation technology, specifically a method for voltage and current control during the tantalum capacitor formation process. Step 1: Input the operating voltage and current parameter curves, as well as voltage and current alarm values, into the PLC automatic controller through the human-machine interface. Step 2: Adjust the power supply output voltage based on the difference between the voltage value across the tantalum capacitor product and the set value, eliminating the voltage division effect of connecting wires and contact points during the tantalum capacitor formation process. Step 3: The PLC automatic controller uses the calculated results to determine whether there are any abnormalities in the feedback voltage and current at the tantalum capacitor product. This invention adjusts the DC power supply output voltage by real-time monitoring the difference between the voltage value across the tantalum capacitor product and the set value, eliminating the voltage division effect of connecting wires and contact points during the tantalum capacitor formation process, increasing the sampling frequency, and automatically determining whether there are abnormal fluctuations in voltage and current through calculation.

Description

Technical Field

[0001] This invention relates to the field of tantalum capacitor formation technology, specifically a method for controlling voltage and current during the tantalum capacitor formation process. Background Technology

[0002] During the formation of tantalum capacitors, voltage and current conditions need to be set to achieve the anodic oxidation chemical reaction of water electrolysis. The deviation of the actual voltage and current values ​​has a great impact on the consistency of the tantalum capacitor formation result (anodic oxide layer thickness). Therefore, it is necessary to monitor and manage the voltage and current values ​​during the tantalum capacitor formation process.

[0003] Current control technology involves setting the voltage and current values ​​of the DC power supply before tantalum capacitor formation, reading and recording the output voltage and current values ​​of the DC power supply, and simultaneously checking and recording the actual voltage value of the tantalum product during the tantalum capacitor formation process for process control. However, the following shortcomings still exist:

[0004] 1. Due to the influence of the connecting wires and contact points between the DC power supply and the tantalum capacitor, the terminal voltage of the tantalum capacitor will be lower than the output voltage of the DC power supply. This voltage difference is affected by the length of the wires and the surface condition of the contact points, and is usually composed of two parts: a fixed constant and a percentage of the set voltage. Therefore, although the voltage difference can be compensated for by personal experience, it cannot be precisely controlled, and it cannot be guaranteed that the product voltage will be consistent every time the tantalum capacitor is manufactured.

[0005] 2. Although the power supply can record process voltage and current, and the process inspection also records voltage, it is still not precise enough to monitor abnormal states throughout the entire process.

[0006] Therefore, those skilled in the art have provided a method for voltage and current control in the formation process of tantalum capacitors to solve the problems mentioned in the background art. Summary of the Invention

[0007] The purpose of this invention is to provide a method for controlling voltage and current during the formation process of tantalum capacitors, so as to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a method for voltage and current control during the formation process of tantalum capacitors, involving the following equipment:

[0009] Power supply: DC power is used for energy supply;

[0010] Voltage measurement unit: used to measure the voltage value at the terminals of tantalum capacitors during the formation process;

[0011] Current measurement unit: used to measure the current value during the formation process of tantalum capacitor products;

[0012] Data acquisition unit: used to acquire the measured voltage and current values ​​at the tantalum capacitor product end in real time;

[0013] PLC automatic controller: used to input the change curves of voltage and current parameters, control the power supply to give output commands, adjust the output of DC power supply according to the comparison results of actual value and set value, and judge whether there is any abnormality in the feedback voltage and current at the tantalum capacitor product end according to the software calculation formula results;

[0014] Human-machine interface unit: used to control the PLC controller and retrieve test results;

[0015] The voltage and current control methods for the aforementioned equipment used in the tantalum capacitor formation process are as follows:

[0016] Step 1: Input the working voltage and current parameter curves, as well as voltage and current alarm values, into the PLC automatic controller through the human-machine interface.

[0017] Step 2: Adjust the power supply output voltage based on the difference between the voltage value across the tantalum capacitor product and the set value in real time monitoring to eliminate the voltage drop effect of connecting wires and contact points during the tantalum capacitor formation process;

[0018] Step 3: The PLC automatic controller uses the calculated results to determine whether there are any abnormalities in the feedback voltage and current at the tantalum capacitor product end.

[0019] As a further aspect of the present invention: the operating voltage and current parameter curves in step 1 are obtained by integrating multiple voltage and current conditions using segmented execution capability. Each operating segment can be independently configured to handle abnormal voltage or current fluctuations. The specific segments are as follows:

[0020] The first segment: Current working mode, working at a constant current value Ia until time Ta. During this process, the oxide layer Ta2O5 thickens and the circuit resistance gradually increases, and the voltage gradually rises to Ua. During this process, abnormal voltage fluctuations are monitored.

[0021] Second section: Voltage operation mode. The voltage rises from Ua to Ub at a certain slope at time Tb. During this process, the oxide layer Ta2O5 thickens and the circuit resistance gradually increases. The current gradually decreases from Ia to Ib. During this process, abnormal fluctuations in the current are monitored.

[0022] The third stage: voltage operation mode, operating at a constant voltage value Ub until time Tc. During this process, the resistance of the circuit will gradually increase as the oxide layer Ta2O5 thickens, and the current will gradually decrease from Ib to Ic. During this process, abnormal fluctuations in the current are monitored.

[0023] As a further solution of the present invention: the voltage abnormal fluctuation monitoring method in step 3: when the tantalum capacitor is working in current mode during the formation process, the current changes according to the preset curve. Because the tantalum anode will generate a Ta2O5 oxide layer and it will gradually thicken, the circuit resistance R will become larger and larger, so the voltage U=I*R will slowly increase until Umax.

[0024] Assuming the real-time voltage measurement at the tantalum capacitor product terminal is U2, and the real-time voltage measurement before time Δt (a settable value) is UΔt, set the voltage abnormal fluctuation alarm parameter x (which can be negative). When U2 - UΔt ≥ x, it is judged as normal; otherwise, it is judged as an abnormal fluctuation. Refer to the schematic diagram ( Figure 3 () Figure 4 As voltage data is continuously collected, U2 and U△t are also constantly updated, enabling full-process monitoring of voltage fluctuations.

[0025] As a further aspect of the present invention: monitoring of abnormal current fluctuations in step 3: when the tantalum capacitor is working in voltage mode during its formation process, the voltage changes according to a preset curve. Because the anode tantalum will generate a Ta2O5 oxide layer and gradually thicken, the circuit resistance R will become larger and larger, so the current I=U / R will slowly decrease until Imin.

[0026] Assuming the real-time current measurement at the tantalum capacitor product end is I2, and the real-time current measurement before time Δt (a settable value) is IΔt, set the current abnormal fluctuation alarm parameter y (which can be negative). When I2 - IΔt ≤ y, it is judged as normal; otherwise, it is judged as an abnormal fluctuation. Refer to the schematic diagram ( Figure 5 () Figure 6 As current data is continuously collected, I2 and IΔt are also continuously updated, realizing full-process monitoring of current fluctuation status.

[0027] As a further embodiment of the present invention, the method for adjusting the power supply output voltage in step 2 is as follows:

[0028] Assuming the set voltage is U0, the power supply output voltage is U1, and the real-time measured voltage at the tantalum capacitor product end is U2, U2 is usually < U1 due to the influence of wire resistance and contact resistance.

[0029] Upon startup, the automatic system issues a command to set U1=U0. Then, the system reads the value of U2 and compares it with the difference between U2 and U0. When U2 < U0, the value of U1 is increased until U2 = U0. When U2 > U0 or the difference between U2 and U0 exceeds the standard, an abnormal prompt is given. In this way, the influence of line resistance and contact resistance can be automatically eliminated, ensuring that the voltage value at the product end of the tantalum capacitor is consistent with the set value during the formation process, and improving the consistency of the anodized layer thickness.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] This invention employs automatic control at the product end of tantalum capacitor formation. By real-time monitoring of the difference between the voltage value at both ends of the tantalum capacitor product and the set value, the output voltage of the DC power supply is adjusted, eliminating the voltage drop effect of connecting wires and contact points during the tantalum capacitor formation process.

[0032] This invention increases the frequency of automatic acquisition of voltage and current values ​​during the formation process of tantalum capacitors. It automatically determines whether there are abnormal fluctuations in voltage and current through calculation, and automatically records the abnormal point data and time to give an abnormal status prompt. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of a voltage and current control method used in the formation process of tantalum capacitors.

[0034] Figure 2 This is a graph showing the segmented execution of operating voltage and current parameters in a voltage and current control method used in the formation process of tantalum capacitors.

[0035] Figure 3 This is a schematic diagram of a voltage and current control method used in the formation process of tantalum capacitors when the voltage is normal.

[0036] Figure 4 This is a schematic diagram of a voltage abnormality control method used in the formation process of tantalum capacitors.

[0037] Figure 5 This is a schematic diagram of a voltage and current control method used in the formation process of tantalum capacitors when the current is normal.

[0038] Figure 6 This is a schematic diagram of an abnormal current situation in a voltage and current control method used in the formation process of tantalum capacitors. Detailed Implementation

[0039] Please see Figures 1-6 In this embodiment of the invention, a method for controlling voltage and current during the formation process of a tantalum capacitor involves the following equipment:

[0040] Power supply: DC power is used for energy supply;

[0041] Voltage measurement unit: used to measure the voltage value at the terminals of tantalum capacitors during the formation process;

[0042] Current measurement unit: used to measure the current value during the formation process of tantalum capacitor products;

[0043] Data acquisition unit: used to acquire the measured voltage and current values ​​at the tantalum capacitor product end in real time;

[0044] PLC automatic controller: used to input the change curves of voltage and current parameters, control the power supply to give output commands, adjust the output of DC power supply according to the comparison results of actual value and set value, and judge whether there is any abnormality in the feedback voltage and current at the tantalum capacitor product end according to the software calculation formula results;

[0045] Human-machine interface unit: used to control the PLC controller and retrieve test results;

[0046] The voltage and current control methods for the aforementioned equipment used in the tantalum capacitor formation process are as follows:

[0047] Step 1: Input the working voltage and current parameter curves, as well as voltage and current alarm values, into the PLC automatic controller through the human-machine interface.

[0048] Step 2: Adjust the power supply output voltage based on the difference between the voltage value across the tantalum capacitor product and the set value in real time monitoring to eliminate the voltage drop effect of connecting wires and contact points during the tantalum capacitor formation process;

[0049] Step 3: The PLC automatic controller uses the calculated results to determine whether there are any abnormalities in the feedback voltage and current at the tantalum capacitor product end.

[0050] Furthermore, the operating voltage and current parameter curves in step 1 are derived by integrating multiple voltage and current conditions using segmented execution capability. Each operating segment can be independently configured to handle abnormal voltage or current fluctuations. The specific segments are as follows:

[0051] The first segment: Current working mode, working at a constant current value Ia until time Ta. During this process, the oxide layer Ta2O5 thickens and the circuit resistance gradually increases, and the voltage gradually rises to Ua. During this process, abnormal voltage fluctuations are monitored.

[0052] Second section: Voltage operation mode. The voltage rises from Ua to Ub at a certain slope at time Tb. During this process, the oxide layer Ta2O5 thickens and the circuit resistance gradually increases. The current gradually decreases from Ia to Ib. During this process, abnormal fluctuations in the current are monitored.

[0053] The third stage: voltage operation mode, operating at a constant voltage value Ub until time Tc. During this process, the resistance of the circuit will gradually increase as the oxide layer Ta2O5 thickens, and the current will gradually decrease from Ib to Ic. During this process, abnormal fluctuations in the current are monitored.

[0054] Furthermore, in step 3, the method for monitoring abnormal voltage fluctuations is as follows: When the tantalum capacitor operates in current mode during its formation process, the current changes according to a preset curve. Because the tantalum anode will generate a Ta2O5 oxide layer and gradually thicken, the circuit resistance R will become larger and larger, so the voltage U=I*R will slowly increase until Umax.

[0055] Assuming the real-time voltage measurement at the tantalum capacitor product terminal is U2, and the real-time voltage measurement before time Δt (a settable value) is UΔt, set the voltage abnormal fluctuation alarm parameter x (which can be negative). When U2 - UΔt ≥ x, it is judged as normal; otherwise, it is judged as an abnormal fluctuation. Refer to the schematic diagram ( Figure 3 () Figure 4 As voltage data is continuously collected, U2 and U△t are also constantly updated, enabling full-process monitoring of voltage fluctuations.

[0056] Furthermore, in step 3, monitoring of abnormal current fluctuations: When the tantalum capacitor operates in voltage mode during its formation process, the voltage changes according to the preset curve. Because the tantalum anode will generate a Ta2O5 oxide layer and gradually thicken, the circuit resistance R will become larger and larger, so the current I=U / R will slowly decrease until Imin.

[0057] Assuming the real-time current measurement at the tantalum capacitor product end is I2, and the real-time current measurement before time Δt (a settable value) is IΔt, set the current abnormal fluctuation alarm parameter y (which can be negative). When I2 - IΔt ≤ y, it is judged as normal; otherwise, it is judged as an abnormal fluctuation. Refer to the schematic diagram ( Figure 5 () Figure 6 As current data is continuously collected, I2 and IΔt are also continuously updated, realizing full-process monitoring of current fluctuation status.

[0058] Furthermore, the method for adjusting the power supply output voltage in step 2 is as follows:

[0059] Assuming the set voltage is U0, the power supply output voltage is U1, and the real-time measured voltage at the tantalum capacitor product end is U2, U2 is usually < U1 due to the influence of wire resistance and contact resistance.

[0060] Upon startup, the automatic system issues a command to set U1=U0. Then, the system reads the value of U2 and compares it with the difference between U2 and U0. When U2 < U0, the value of U1 is increased until U2 = U0. When U2 > U0 or the difference between U2 and U0 exceeds the standard, an abnormal prompt is given. In this way, the influence of line resistance and contact resistance can be automatically eliminated, ensuring that the voltage value at the product end of the tantalum capacitor is consistent with the set value during the formation process, and improving the consistency of the anodized layer thickness.

[0061] In summary, this invention employs automatic control at the tantalum capacitor formation product end. By real-time monitoring of the voltage difference between the two ends of the tantalum capacitor product and the set value, the output voltage of the DC power supply is adjusted, eliminating the voltage drop effect of connecting wires and contact points during the tantalum capacitor formation process.

[0062] This invention increases the frequency of automatic acquisition of voltage and current values ​​during the formation process of tantalum capacitors. It automatically determines whether there are abnormal fluctuations in voltage and current through calculation, and automatically records the abnormal point data and time to give an abnormal status prompt.

[0063] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A voltage and current management approach for a tantalum capacitor formation process, comprising: The application relates to a device for monitoring voltage and current of tantalum capacitor products during a formation process. Power supply: direct current is used for energy supply; A voltage measuring unit is used for measuring voltage values of the tantalum capacitor products during a formation process; A current measuring unit is used for measuring current values of the tantalum capacitor products during a formation process; A data acquisition unit is used for acquiring the measured voltage and current values of the tantalum capacitor products in real time; A PLC automatic controller is used for inputting a change curve of voltage and current parameters, controlling output instructions of the power supply, adjusting output values of the direct current power supply according to comparison results of actual values and set values, and judging whether feedback voltage and current of the tantalum capacitor products are abnormal according to calculation results; A man-machine interactive unit is used for controlling the PLC controller and calling test results. The device is used for voltage and current control methods of the tantalum capacitor formation process, and the methods are as follows: Step 1: inputting working voltage, current parameter curves and voltage and current alarm values into the PLC automatic controller through an interface of the man-machine interactive unit; Step 2: adjusting output voltage of the power supply according to a difference between voltage values of the tantalum capacitor products and set values, and eliminating the influence of voltage division of connecting wires and contact points during the tantalum capacitor formation process; Step 3: judging whether feedback voltage and current of the tantalum capacitor products are abnormal according to calculation results of the PLC automatic controller.

2. A voltage and current management approach for a tantalum capacitor formation process as claimed in claim 1, wherein, The working voltage and current parameter curves in step 1 are obtained by integrating various voltage and current conditions through segmented execution ability, each running segment can independently set voltage or current abnormal fluctuation, and the segments are as follows: The first segment: current working mode, working at a constant current value Ia to time Ta, in the process, the oxide layer Ta2O5 thickens, the loop resistance gradually increases, the voltage gradually rises to Ua, and voltage abnormal fluctuation is monitored in the process; The second segment: voltage working mode, the voltage rises from Ua to Ub at a certain slope at time Tb, in the process, the oxide layer Ta2O5 thickens, the loop resistance gradually increases, the current gradually decreases from Ia to Ib, and current abnormal fluctuation is monitored in the process; The third segment: voltage working mode, working at a constant voltage value Ub to time Tc, in the process, the oxide layer Ta2O5 thickens, the loop resistance gradually increases, the current gradually decreases from Ib to Ic, and current abnormal fluctuation is monitored in the process.

3. The voltage and current management approach for the formation process of tantalum capacitors according to claim 1 or 2, characterized in that, The voltage abnormal fluctuation monitoring method in step 3: when working in the current mode during the tantalum capacitor formation process, the current changes according to the preset curve, the Ta2O5 oxide layer is generated on the anode tantalum and slowly thickens, the loop resistance R gradually increases, and therefore the voltage U=I*R slowly increases until Umax; Supposing that the real-time voltage measurement value of the tantalum capacitor product end is U2, the real-time voltage measurement value before time △t is U△t, the set voltage abnormal fluctuation alarm parameter x is determined, when U2-U△t >= x, it is determined to be normal, otherwise it is determined to be abnormal fluctuation, with the voltage data being continuously collected, U2 and U△t are also continuously updated, and voltage fluctuation state monitoring in the whole process is realized.

4. The voltage and current management approach for the formation process of tantalum capacitors according to claim 1 or 2, characterized in that, Step 3: Current abnormal fluctuation monitoring: In the tantalum capacitor formation process, when working in voltage mode, the voltage changes according to the preset curve. The anode tantalum generates Ta2O5 oxide layer and slowly thickens, the loop resistance R becomes larger, so the current I=U / R slowly decreases until Imin; Assuming that the real-time current measurement value of the tantalum capacitor product end is I2, the real-time current measurement value before time △t is I△t, and the current abnormal fluctuation alarm parameter y is set, when I2-I△t ≤ y, it is determined to be normal, otherwise it is determined to be abnormal fluctuation. With continuous collection of current data, I2 and I△t are also continuously updated, realizing the whole process of current fluctuation state monitoring.

5. The voltage and current management approach for tantalum capacitor formation process of claim 1, wherein, Step 2: Power output voltage adjustment method as follows: Assuming that the set voltage is U0, the power output voltage is U1, and the real-time measurement voltage of the tantalum capacitor product end is U2, usually U2<U1 due to the influence of wire resistance and contact resistance; When starting, the automatic system gives instructions to let U1=U0, then the system reads the U2 value and compares the difference between U2 and U0. When U2<U0, increase U1 value until U2=U0. When U2>U0 or the difference between U2 and U0 exceeds the standard, give an abnormal prompt. In this way, the influence of wire resistance and contact resistance can be automatically eliminated, and the voltage value of the tantalum capacitor product end in the formation process can be ensured to be consistent with the set value.

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